A key Senate committee unveiled legislation Monday to keep the government funded through the end of September while reducing the impact of $85 billion in forced spending cuts on a number of major federal programs.

The full Democratic-controlled Senate is expected to vote on the Appropriations Committee's spending bill, known in Washington as a continuing resolution, before the end of the week. The measure builds on a bill passed by the Republican-run House of Representatives on March 6.

Among other things, the Senate bill would allow greater flexibility for the departments of Homeland Security, Justice, Agriculture, and Commerce -- as well as NASA -- as they manage the implementation of the recently imposed cuts. It also incorporates the House GOP's call for similar flexibility at the departments of Defense and Veterans Affairs.

Leaders in both chambers are trying to reach an agreement on spending for the rest of the fiscal year before March 27, when the current government spending authorization expires.

A partial government shutdown would occur if Congress fails to extend funding authorization by the deadline, but top officials in both parties say they don't want another political showdown over the legislation.

"We must prevent a government shutdown," said Maryland Democratic Sen. Barbara Mikulski, the chairman of the Appropriations Committee. This measure "lets us wrap up fiscal year 2013 so we can get to next year's budget and find a balanced solution to sequester."

"At a time when many doubt whether Congress can accomplish anything at all, this agreement is a very clear demonstration of our commitment to work together," said Alabama Sen. Richard Shelby, the top Republican on the panel.

Senate Majority Leader Harry Reid, D-Nevada, told reporters last week he's "cautiously optimistic" a deal can be reached. Senate Minority Leader Mitch McConnell, R-Kentucky, said that "there seems to be no interest in either side in having a kind of confrontational government shutdown scenario."